M57: The Ring Nebula from Hubble
Except for the ringsof Saturn, the RingNebula (M57) is probably the most famous celestial circle.Its classic appearance isunderstood to be due to our own perspective, though.The recent mapping of theexpanding nebula’s3-D structure, based in part onthis clear Hubble image,indicates thatthe nebula is a relatively dense, donut-like ring wrappedaround the middle of a (American) football-shaped cloud of glowing gas.
Continue Reading